1. Technical Field
The present disclosure relates to a display driving device, and more particularly, to an output circuit and a switching circuit of a display driving device.
2. Related Art
In many cases, a liquid crystal display (LCD) device is used as a flat panel display device. The LCD device displays a screen using an optical shutter characteristic based on the electrical characteristic of liquid crystal, and may include a source driver integrated circuit (IC), a gate driver IC, and a timing controller in order to drive liquid crystal.
A data signal has information for displaying a screen and is transmitted to the source driver IC from the timing controller, and the source driver IC provides an output signal corresponding to the data signal to a display panel.
The display panel may include an LCD panel. When the LCD panel provides only data signals having the same polarity, the LCD panel may have difficulties in forming a normal screen due to a liquid crystal driving error.
Hereafter, the source driver IC will be referred to as a display driving device. The display driving device may include a digital block and an output circuit. The digital block may process a data signal, and the output circuit may provide a signal converted by a digital-to-analog converter to the display panel. The digital block may be designed to perform a signal processing operation using a low voltage, and the output circuit may be designed to be driven by a high voltage. Since such an output circuit is driven by a high voltage, the output circuit may consume a large amount of power.
Furthermore, the output circuit may include an output buffer unit and a switching unit. The output buffer may be driven at a low voltage in order to reduce power consumption, and the switching unit may be driven at a high voltage. In this case, since the output buffer unit and the switching unit have different driving voltage ranges, the display driving device may not have a stable electrical characteristic.